Fig. 5

Twostep chemobiocatalytic synthesis of BHMF from glucose: (A) reaction scheme; (B) effect of MeTHF/water volume ratios on HMF synthesis; effect of Ca²⁺ concentrations (C) and MeTHF/water volume ratios (D) on biocatalytic BHMF synthesis; (E) biocatalytic production of BHMF from HMF obtained by chemocatalysis. Reaction conditions: (B) 0.25 g glucose, 0.6 g CaCl₂, 2.5 mL deionized water, 80 °C, 1 h; then, adding 0.63-10 mL MeTHF, 200 °C, 2 h; (C) 50 mM HMF, 50 mM glucose, 0–1 M CaCl₂, 60 mg/mL cells, 2.5 mL Tris-HCl buffer (0.1 M, pH 8), 30 ℃, 200 rpm, 6 h; (D) 50 mM HMF, 50 mM glucose, 60 mg/mL cells, 2.5 mL Tris-HCl buffer (0.1 M, pH 8), 0.63-10 mL MeTHF, 30 ℃, 200 rpm, 6 h; (E) approximately 110 mM crude HMF, 110 mM glucose, 60 mg/mL cells, 5 mL pH 8 aqueous solution, 30 ℃, 200 rpm